1 files changed, 82 insertions, 0 deletions
diff --git a/lib/puppet/parser/ast/hostclass.rb b/lib/puppet/parser/ast/hostclass.rb
new file mode 100644
index 000000000..a5a228716
--- /dev/null
+++ b/lib/puppet/parser/ast/hostclass.rb
@@ -0,0 +1,82 @@
+class Puppet::Parser::AST
+    # The code associated with a class.  This is different from components
+    # in that each class is a singleton -- only one will exist for a given
+    # node.
+    class HostClass < AST::Component
+        @name = :class
+        attr_accessor :parentclass
+
+        def evaluate(scope,hash,objtype,objname)
+            if scope.lookupclass(@name)
+                Puppet.debug "%s class already evaluated" % @name
+                return nil
+            end
+
+            if tmp = self.evalparent(scope, hash, objname)
+                # Override our scope binding with the parent scope
+                # binding. This is quite hackish, but I can't think
+                # of another way to make sure our scopes end up under
+                # our parent scopes.
+                scope = tmp
+            end
+
+            # just use the Component evaluate method, but change the type
+            # to our own type
+            retval = super(scope,hash,@name,objname)
+
+            # Set the mark after we evaluate, so we don't record it but
+            # then encounter an error
+            scope.setclass(@name)
+            return retval
+        end
+
+        # Evaluate our parent class.  Parent classes are evaluated in the
+        # exact same scope as the children.  This is maybe not a good idea
+        # but, eh.
+        def evalparent(scope, args, name)
+            if @parentclass
+                parentobj = nil
+
+                begin
+                    parentobj = scope.lookuptype(@parentclass)
+                rescue Puppet::ParseError => except
+                    except.line = self.line
+                    except.file = self.file
+                    raise except
+                rescue => detail
+                    error = Puppet::ParseError.new(detail)
+                    error.line = self.line
+                    error.file = self.file
+                    raise error
+                end
+                unless parentobj
+                    error = Puppet::ParseError.new( 
+                        "Could not find parent '%s' of '%s'" %
+                            [@parentclass,@name])
+                    error.line = self.line
+                    error.file = self.file
+                    raise error
+                end
+
+                # Verify that the parent and child are of the same type
+                unless parentobj.class == self.class
+                    error = Puppet::ParseError.new(
+                        "Class %s has incompatible parent type, %s vs %s" %
+                        [@name, parentobj.class, self.class]
+                    )
+                    error.file = self.file
+                    error.line = self.line
+                    raise error
+                end
+                return parentobj.safeevaluate(scope,args,@parentclass,name)
+            end
+        end
+
+        def initialize(hash)
+            @parentclass = nil
+            super
+        end
+
+    end
+
+end